I am looking to build a chicken coop in my yard and I am wanting to get about 15-20 chicks after I have it built. I have looked at many different coop designs and sizes but I am not sure what kind of space/nests will be needed for the chickens to be comfortable. Also- is there a good hen-rooster ratio? If you can't tell I'm pretty new at this. I just want to get it right. Thanks for any help!